1. Field
The subject invention is in the field of small structures, specifically collapsible and foldable structures such as step ladders, scaffolds and the like and, more specifically, sawhorses.
2. Prior Art
There is much prior art in this specific field patented and not patented. The patents listed below are a sample of patented prior art sawhorses and related equipment.
______________________________________ U.S. Pat. Nos.: ______________________________________ 249,508 2,558,915 1,435,738 4,752,047 2,986,230 4,911,390 ______________________________________
In each instance the general purposes are to provide a sawhorse or similar support structure which can be collapsed or folded to facilitate transporting and storing the structure and to provide the structure at commercially competitive cost. In each instance also there is an inherent compromise involving the functional utility, the degree of collapsibility and the cost of the structure, the cost of structures of equivalent utility tending to be less for those that are less collapsible. Another important factor in concepts for sawhorses is that the horizontal member, termed the work member for purposes of this application, be made of material which will not harm saws and the like which come into contact with the work member, wood being a material of choice. For cost comparisons of various concepts the cost of the work member can be considered a constant, so that the cost comparisons are based on the costs of the supports, pivots, locks and the like used in the sawhorses.
As noted previously, comparisons of costs of sawhorses are valid only when the sawhorses being compared have equivalent collapsibility. There are two general orders of collapsibility. In one the supports (legs) fold together and up toward the work member such that all the dimensions except the length of the work member are reduced. (In some cases even that dimension is reduced.) In the second order the supports are folded so that the collapsed structure can be characterized as flat and uses a minimum of floor space when stored against or hung on a wall. Sawhorses having this second order of collapsibility are generally recognized as less costly than sawhorses having the first order of collapsibility and more cost effective considering overall utility, first cost, storage space required and time and effort required to erect and collapse. Sawhorses having the second order of collapsibility as defined above are termed foldable sawhorses for purposes of this patent application.
It is well understood in the art that the cost effectiveness of a foldable sawhorse of specific size and utility depends directly on its structural efficiency; that is, its structural requirements are met with relatively few parts, all of simple configuration and a significant portion of them commercially available.
The primary objective of the subject invention is provision of a foldable sawhorse which can be competitively priced because of its high structural efficiency. Corollary objectives are that each of its parts be simple and easy to manufacture, that the number of parts be minimal, that its assembly be simple and that its use be simple and safe.